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19 results on '"Pant, Prahlad D."'

1. Neural network for gap acceptance at stop-controlled intersections

Author

Pant, Prahlad D. and Balakrishnan, Purushothaman

Subjects
Neural networks -- Usage, Roads -- Interchanges and intersections, Traffic engineering -- Methods, Engineering and manufacturing industries, Science and technology, Transportation industry
Abstract

: The behavior of gap acceptance by vehicles at intersections with stop signs involves the complex interaction of numerous geometric, traffic, and environmental factors. Several methods, including empirical analysis, and theoretical, logit, and probit models have been used to estimate gap acceptance at stop-controlled intersections. In the past, neural networks have been used to examine problems involving complex interrelationship among many variables and found to perform better than conventional methods. This paper describes the development of a neural network and a binary-logit model for predicting accepted or rejected gaps at rural, low-volume two-way stop-controlled intersections. The type of control, the turning movements in both the major and minor directions, size of gap, service time, stop type, vehicular speed, queue in the minor direction, and existence of vehicle in the opposite approach were found to influence the driver's decision to accept or reject a gap. The results of the neural network and the binary-logit model were compared with the observations recorded in the field. The results revealed that the neural network correctly predicted a higher percentage of accepted or rejected gaps than the binary-logit model.

Published
1994

2. Crash base rates for freeways/reduction strategies for rear end crashes.

Author

Pant, Prahlad D. and Pant, Prahlad D.

Subjects
Rear-end collisions Ohio., Traffic accidents Research Ohio., Traffic safety Ohio., Chocs par l'arrière Ohio., Accidents de la route Recherche Ohio., Sécurité routière Ohio., Rear-end collisions., Traffic accidents Research., Traffic safety., Accident rates., Ohio.
Abstract

"The primary objective of this research was to systematically review past studies on rear end crashes, examine strategies for reducing rear end crashes on both freeway and non freeway facilities, and develop a set of rear end crash reduction strategies for use in Ohio, which will be appropriate for various traffic engineering solutions, operations and ITS improvements. Accordingly, this study conducted an extensive review of past literature related to rear end crashes and strategies to reduce them. A determination of specific strategies for a road safety improvement program requires an understanding of probable crash reduction capabilities for various geometric, operational and environmental factors on the roadways. Studies of crash reduction strategies have usually focused on before-and-after comparisons of specific locations or conditions. Based on the data provided by the Ohio Department of Transportation, this study attempted to examine the crash reduction capabilities for signalized intersections, unsignalized intersections, freeways and non-freeways where countermeasures were implemented. An attempt was made to compute crash reduction factors for rear end collisions for these roadway facilities. However, this task could not be performed because of the severe limitations in the ODOT countermeasure and roadway site data. In response to the researchers' request for additional data, ODOT decided not to proceed ahead with this research as it required the dedication of district resources that were not currently available. It was believed that breaking the project into smaller, more manageable pieces, would not yield results that would be statistically significant. There were also several national projects underway which would limit this project's benefits. In view of these circumstances, ODOT decided to terminate the contract for this project and all work stopped"--Technical report documentation page

Published
2009

3. Crash base rates for intersections in Ohio

Author

Pant, Prahlad D. and Pant, Prahlad D.

Subjects
Traffic accidents Research Ohio., Roads Interchanges and intersections Safety measures., Accidents de la route Recherche Ohio., Intersections (Technique routière) Sécurité Mesures., Roads Interchanges and intersections Safety measures., Traffic accidents Research., Accident causes., Accident characteristics., Accident rates., Intersections., Accident Causation/ Accident Patterns., Accident Statistics/ Accident Rates., Intersections/ Road Junctions., Ohio., Ohio.
Abstract

A safety analysis of a specific location requires the knowledge of "base crash rates," also known in the literature as "expected values," for identifying crash patterns at the study location. Base crash rate models were developed for the following nine crash types: (a) Injury (b) PDO (c) Total (d) Wet (e) Night (f) Rear end (g) Sideswipe (h) Fixed object and (i) Left turn crashes. These models were developed for intersection legs (also called intersection approaches) as the crash behavior of different legs within the same intersection were likely to be different. Base crash rates for the following eight leg types were modeled based on the type of control: (a) Signalized legs at four way signalized intersections (b) Signalized legs at three way signalized intersections (c) No control legs at one way stop controlled intersections (d) Stop controlled legs at one way stop controlled intersections (e) No control legs at two way stop controlled intersections (f) Stop controlled legs at two way stop controlled intersections (g) No control legs at intersections with flashing beacons and (h) Stop controlled legs at intersections with flashing beacons. This study focused on intersections formed by two or more State or US routes. To evaluate the complex interaction among the dependent and independent variables, Automatic Interaction Detection (AID) technique was used. After the completion of AID analysis, stepwise multiple regression technique was used to develop mathematical models for the split groups. It is recommended that the AID and regression models developed in this study (Appendices II and III) be used for estimating statewide base crash rates in Ohio.

Published
2007

5. Validation of ODOT sufficiency rating system

Author

Pant, Prahlad D. and Pant, Prahlad D.

Subjects
Pavements Performance Mathematical models., Roads Evaluation. Ohio, Chaussées Comportement Modèles mathématiques., Pavements Performance Mathematical models., Roads Evaluation., Safety., Ohio.
Abstract

This study first presents an overview of ODOT's current sufficiency rating (SR) system followed by a comparative study of SR systems in other states. The system developed by ODOT, like most other states, was based on the opinions of an expert panel who, based on their previous knowledge and experience, selected the type and number of parameters including the weights assigned to each parameter. The researchers recommended an objective approach for developing the SR system which consisted of three major variables namely, Condition, Congestion, and Crashes. A statistical technique called Principal Component Analysis was used for developing mathematical models to calculate the sufficiency ratings for 10 functional classifications of highways in the State of Ohio.

Published
2005

7. Implementation and testing of the Travel Time Prediction System (TIPS)

Author

Pant, Prahlad D. and Pant, Prahlad D.

Subjects
Travel time (Traffic engineering) Technological innovations Ohio., Electronic traffic controls Technological innovations Ohio., Durée du trajet (Technique de la circulation) Innovations Ohio., Feux de circulation Innovations Ohio., Electronic traffic controls Technological innovations., Evaluation., Ohio.
Abstract

A freeway construction work zone creates conflicts between vehicular traffic and work activity. The closure of one or more lanes of a freeway section causes a bottleneck on the freeway and reduces the capacity in the work zone, which can lead to conditions that violate the expectations of the motorists. Such a work zone situation is a challenge to one of the main objectives of a traffic management system, that is, to maintain "the safe and efficient movement of traffic." The advance warning area of a traffic control zone represents the area in which the motorists are informed as to what they can expect ahead. The information which is normally provided to the motorists include the type of construction activity, type of lane closure, extent of the work zone, and whether there are available alternate routes to avoid the construction all together. This information is given on static signs, or electronic portable changeable message signs (CMS) by way of static preprogrammed messages.

Published
2001

9. Pedestrian Traffic on Cincinnati Skywalk System

Author

Bhalla, Manmohan K. and Pant, Prahlad D.

Abstract

A method for estimating pedestrian trips on the sky walk system in the central business district of Cincinnati, Ohio has been developed. The central business district experiences congestion and conflicting pedestrin‐vehicle movements, especially at signalized intersections. Attempts have been made to reduce the complexity of the problem by the construction of the skywalk system. Data on pedestrian trips on the skywalk system was obtained from a manual count conducted simultaneously at twelve strategic points on the skywalk system. Land use data was obtained from published sources and from related public and private agencies. Regression analysis was conducted to estimate pedestrian trips on the skywalk system during lunch peak (11:30a.m.–1:30p.m.) and evening peak (3:30p.m.–5:30p.m.). The results have shown that restaurants (number of seats), floor space area for office use (sq ft or m2), floor space area for retail use (sq ft or m2) and hotels (number of rooms) are the most significant independent variables. Parking space was not found significant. The analysis shows that simple quantitative models for estimating pedestrian trips on the skywalk system can be conveniently developed on the basis of a relatively simple data base.

Published
1985

10. Implementation and testing of the travel time prediction system (TIPS) : executive summary, May 2001.

Author

Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., University of Cincinnati. Department of Civil and Environmental Engineering, Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., and University of Cincinnati. Department of Civil and Environmental Engineering

Abstract

14756(0), The Travel Time Prediction System (TIPS) is a portable automated system for predicting and displaying travel time for motorists in advance of and through freeway construction work zones, on a real-time basis. It collects real-time traffic flow data using ;Sponsored by Federal Highway Administration, Columbus, OH. Ohio Div. and Ohio Dept. of Transportation, Columbus.

11. Methodology for assessing the effectiveness of access management techniques : executive summary.

Author

Ohio. Dept. of Transportation, Pant, Prahlad D., Ula, Md. Sadrul, Liu, Yuejiao, University of Cincinnati. Department of Civil and Environmental Engineering, Ohio. Dept. of Transportation, Pant, Prahlad D., Ula, Md. Sadrul, Liu, Yuejiao, and University of Cincinnati. Department of Civil and Environmental Engineering

Abstract

14660(0), A methodology for assessing the effectiveness of access management techniques on suburban arterial highways is developed. The methodology is described as a seven-step process as follows: (1) establish the purpose of the analysis (2) establish the measures;See also PB96-187043. Sponsored by Federal Highway Administration, Columbus, OH. Ohio Div. and Ohio Dept. of Transportation, Columbus.;pg 154

12. Dilemma zone protection and signal coordination at closely-spaced high-speed intersections : executive summary, November 2001.

Author

Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, University of Cincinnati, Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, and University of Cincinnati

Abstract

14673(0), A feasibility study of dilemma zone problems, performed by collecting and analyzing traffic flow data at a high-speed signalized intersection, showed that the maximum green extension or cutback needed to get a vehicle out of the dilemma zone is generally no more than two seconds. Scanning all vehicles on a link just seconds before the beginning of a yellow interval may extend or cut back the green interval so that vehicles can avoid the dilemma zone. For each vehicle approaching an intersection on a link about to turn yellow there is a time interval that (a) the vehicle will be in dilemma zone without green extension (or cutback) or (b) it will be in dilemma zone when there is T seconds of extension (or cutback). The task becomes to find the smallest nonnegative integer T that is not in any of these time intervals and extend or cutback the current interval by T seconds. This T can always be found and assuming there are no other restrictions, dilemma zones can be avoided and the extension or cutback is done at most once for each green interval. The simulation study, performed by modifying the source codes of NETSIM, showed that the signal timing generated by a bandwidth maximization program (PASSER II) resulted in a lower number of vehicles in dilemma zone than that generated by a delay minimization program (TRANSYT-7F). Additionally, the signal timing generated by the combination of the two programs, that is, by minimizing delay within the constraint of bandwidth maximization, resulted in even lower number of vehicles in dilemma zone than those generated by each program alone. The technique developed in this study can be implemented if the speeds and positions of all vehicles in the roadway can be recorded at small time intervals (e.g., 1 sec.). Recommendations are made for implementing and testing the developed technique

13. Dilemma zone protection and signal coordination at closely-spaced high-speed intersections : final report, November 2001.

Author

Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, University of Cincinnati, Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, and University of Cincinnati

Abstract

A feasibility study of dilemma zone problems, performed by collecting and analyzing traffic flow data at a high-speed signalized intersection, showed that the maximum green extension or cutback needed to get a vehicle out of the dilemma zone is generally no more than two seconds. Scanning all vehicles on a link just seconds before the beginning of a yellow interval may extend or cut back the green interval so that vehicles can avoid the dilemma zone. For each vehicle approaching an intersection on a link about to turn yellow there is a time interval that (a) the vehicle will be in dilemma zone without green extension (or cutback) or (b) it will be in dilemma zone when there is T seconds of extension (or cutback). The task becomes to find the smallest nonnegative integer T that is not in any of these time intervals and extend or cutback the current interval by T seconds. This T can always be found and assuming there are no other restrictions, dilemma zones can be avoided and the extension or cutback is done at most once for each green interval. The simulation study, performed by modifying the source codes of NETSIM, showed that the signal timing generated by a bandwidth maximization program (PASSER II) resulted in a lower number of vehicles in dilemma zone than that generated by a delay minimization program (TRANSYT-7F). Additionally, the signal timing generated by the combination of the two programs, that is, by minimizing delay within the constraint of bandwidth maximization, resulted in even lower number of vehicles in dilemma zone than those generated by each program alone. The technique developed in this study can be implemented if the speeds and positions of all vehicles in the roadway can be recorded at small time intervals (e.g., 1 sec.). Recommendations are made for implementing and testing the developed technique.

14. Field testing and implementation of dilemma zone protection and signal coordination at closely-spaced high-speed intersections : research implementation plan.

Author

Ohio. Dept. of Transportation. Office of Research and Development, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, Rajagopal, Arudi, Kashayi, Nagaraju, University of Cincinnati. Department of Civil and Environmental Engineering, Ohio. Dept. of Transportation. Office of Research and Development, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, Rajagopal, Arudi, Kashayi, Nagaraju, and University of Cincinnati. Department of Civil and Environmental Engineering

Abstract

14754(0), The Area closed to a Signalized intersection called, the Dilemma Zone Poses a high accident potential for, the Driver in stopping safely. The uncertain situation, in a dilemma zone can potentially lead to rear-end or, right angle collisions. We recommend this method for, reducing dilemma zone problems.

15. Implementation and testing of the travel time prediction system (TIPS) : final report, May 2001.

Author

Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., University of Cincinnati. Department of Civil and Environmental Engineering, Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., and University of Cincinnati. Department of Civil and Environmental Engineering

Abstract

14756(0), The Travel Time Prediction System (TIPS) is a portable automated system for predicting and displaying travel time for motorists in advance of and through freeway construction work zones, on a real-time basis. It collects real-time traffic flow data using ;Sponsored by Federal Highway Administration, Columbus, OH. Ohio Div. and Ohio Dept. of Transportation, Columbus.

16. Field testing and implementation of dilemma zone protection and signal coordination at closely-spaced high-speed intersections : final report, May 19, 2005.

Author

Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, Rajagopal, Arudi, Kashayi, Nagaraju, University of Cincinnati. Department of Civil and Environmental Engineering, Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, Rajagopal, Arudi, Kashayi, Nagaraju, and University of Cincinnati. Department of Civil and Environmental Engineering

Abstract

14754(0), The report presents the details of a study carried out to test and implement a dilemma zone protection technique at three high-speed closely-spaced intersections on Roosevelt Blvd in Middletown, Ohio.

17. Field testing and implementation of dilemma zone protection and signal coordination at closely-spaced high-speed intersections : executive summary report.

Author

Ohio. Dept. of Transportation. Office of Research and Development, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, Rajagopal, Arudi, Kashayi, Nagaraju, University of Cincinnati. Department of Civil and Environmental Engineering, Ohio. Dept. of Transportation. Office of Research and Development, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, Rajagopal, Arudi, Kashayi, Nagaraju, and University of Cincinnati. Department of Civil and Environmental Engineering

Abstract

14754(0), The area close to a signalized intersection, called the dilemma zone, poses a high accident, potential for the driver in stopping safely during the, yellow interval or in proceeding through the, intersection before the beginning of red. Generally, the location of the driver on the intersection, approach and the speed of the vehicle influence the, driver’s decision to stop or proceed when he sees, the green signal changing to yellow. The clearing, distance is the distance the vehicle travels between, the time the signal changes to yellow to the time the, signal changes to red. The stopping distance is the, distance traveled by the vehicle between the time, the signal changes to yellow to the time when the, vehicle actually comes to rest. If the stopping, distance is greater than the clearing distance, and, the vehicle is placed in between them, a dilemma, zone is formed. In this situation, neither the distance, to the intersection is adequate for stopping nor is the, signal interval adequate for clearing the, intersection. The driver is in a potentially hazardous, situation whereby, if he tries to cross the, intersection at the onset of red interval, he may end, up in an angle accident with the cross street traffic, or if he accelerates through yellow, he may end up, in a rear-end collision. The uncertain situation in a, dilemma zone can potentially lead to rear-end or, right angle collisions.

18. Dilemma zone protection and signal coordination at closely-spaced high-speed intersections : research implementation plan, November 2001.

Author

Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, University of Cincinnati, Ohio. Dept. of Transportation, United States. Federal Highway Administration, Pant, Prahlad D., Cheng, Yizong, and University of Cincinnati

Abstract

14673, Assess the feasibility of reducing decision Zone (also, call dilemma Zone) through adjustments of signal, timing.

19. Methodology for assessing the effectiveness of access management techniques : final report, September 14, 1998.

Author

Ohio. Dept. of Transportation, Pant, Prahlad D., Ula, Md. Sadrul, Liu, Yuejiao, University of Cincinnati. Department of Civil and Environmental Engineering, Ohio. Dept. of Transportation, Pant, Prahlad D., Ula, Md. Sadrul, Liu, Yuejiao, and University of Cincinnati. Department of Civil and Environmental Engineering

Abstract

14660(0), A methodology for assessing the effectiveness of access management techniques on suburban arterial highways is developed. The methodology is described as a seven-step process as follows: (1) establish the purpose of the analysis (2) establish the measures;See also PB96-187043. Sponsored by Federal Highway Administration, Columbus, OH. Ohio Div. and Ohio Dept. of Transportation, Columbus.;pg 154

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